Recent studies have indicated that vascular smooth muscle cells in a variety of vascular beds express enzymes of the cytochrome P450 4A and related families (CYP 4A) that catalyze the formation of 20-hydroxyeicosatetraenoic acid (20-HETE). 20-HETE is a potent constrictor (EC50 less than 10xe2x88x928 M) of renal, cerebral and skeletal muscle arterioles. It promotes Ca2+ entry by depolarizing VSM cells secondary to blockade of KCa channels and by increasing the conductance of L-type Ca2+ channels (Harder, D., J. Vasc. Research 34:237-243, 1997; Roman, R., News in Physiological Sciences, 1999, in press). In the kidney, 20-HETE is also produced by renal tubular cells where it participates in the regulation of sodium transport in the proximal tubule and thick ascending limb of the loop of Henle. In (Roman R., Supra, 1999) human and rabbit lung, 20-HETE is also produced by the airways where it serves as an potent endogenously produced bronchodilator (Zhu, D., Am. J. Resp. Cell Mol. Biol. 19:121-128, 1998; Jacobs, E. R., Am. J. Physiol. 1999, in press).
Despite the importance of 20-HETE in the regulation of vascular tone, kidney function, and airway resistance, little is known of its mechanism of action. Recent studies have indicated that the vasoconstrictor response to 20-HETE and its inhibitory actions on sodium transport is associated with activation of PKC and MAP kinase signal transduction cascades(Sun, C. -W., Hypertension 33:414-418, 1999). Activation of these pathways are usually triggered by receptor mediated events, however, at present time there is no evidence for a 20-HETE receptor. To date, there have been no published studies to determine whether 20-HETE binds to membrane or cytosolic proteins or to determine whether the vasoconstrictor response is specific to 20-HETE or can be mimicked by closely related analogs.
The present invention springs from a study designed to perform structure activity studies with a series of 20-HETE analogs to determine the structural determinants to the vasoconstrictor response in interlobular arteries microdissected from the kidney of rats.
In one embodiment, the invention is a method of reducing a patient""s vascular diameter or preventing 20-HETE from reducing vascular diameter, comprising the step of supplying to the patient an effective amount of a 20-HETE agonist or antagonist.
Preferably, the compound is of the following formula: 
R1 is selected from the group consisting of carboxylic acid; phenol; amide; imide; sulfonamide; sulfonimide; active methylene; 1,3-dicarbonyl; alcohol; thiol; amine; tetrazole or other heteroaryl;
R2 is selected from the group consisting of carboxylic acid; phenol; amide; imide; sulfonamide; sulfonimide; active methylene; 1,3-dicarbonyl; alcohol; thiol; amine; tetrazole or other heteroaryl;
W is a carbon chain (C1 through C25) and may be linear, cyclic, or branched and may comprise heteroatoms, such as S, O, N or Se;
Y is a carbon chain (C1 through C25) and may be linear, cyclic, or branched and may comprise heteroatoms such as S, O, N or Se;
sp less than 3 Center is selected from the group consisting of vinyl; aryl; heteroaryl; cyclopropyl; and acetylenic moieties;
X is an alkyl (linear, branched, cyclic or polycyclic) group with or without heteroatoms; or a vinyl; aryl; heteroaryl; cyclopropyl; or acetylenic group;
m=0, 1, 2, 3, 4 or 5 and n=0, 1, 2, 3, 4 or 5.
In a preferred embodiment of the method, the compound is an agonist and vascular diameter is reduced or bronchiole smooth muscle is dilated. In this embodiment, the compound is a 20-HETE agonist. Preferably, the agonist compound is selected from the group consisting of 21-hydroxyheneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid; 20-hydroxyeicosa-5(Z),14(Z)-dienoic acid; and dimethyl 20-HETE.
In another embodiment of the method, the compound is a 20-HETE antagonist and the vascular diameter is prevented from being reduced by endogenous 20-HETE. Preferably, the compound is selected from the group consisting of 5(S)-HETE; 15(S)-HETE; 19(S)-HETE; 19-hydroxynonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid (C19 analog); and 20-hydroxyeicosa 6(Z),15(Z)-dienoic acid (Ps rev 20-HETE).
In another embodiment, the present invention is a method of treating a patient comprising the steps of supplying an effective amount of a 20-HETE agonist or antagonist.
In another embodiment, the patient has a disease selected from the group consisting of diabetes, toxemia of pregnancy (preeclampsia), hepatorenal syndrome, cyclosporin-induced nephrotoxicity, cerebral vasospasm, stroke, and hypertension and the vasoconstrictor actions of the patient""s excess endogenously-produced 20-HETE is moderated when treated with a 20-HETE antagonist.
In another embodiment, the patient has septic shock or other inflammatory disease associated with induction of nitric oxide synthase and is treated with an amount of 20-HETE antagonist sufficient to reduce symptoms.
In another embodiment, patients are treated with a 20-HETE antagonist to prevent vascularization of granular or neoplastic tissues. This treatment reduces blood supply and prevents growth of tumors.
In another embodiment, the patient has a condition selected from the group of congestive heart failure, pulmonary edema, hepatorenal syndrome and hypertension and is treated with an amount of 20-HETE agonist sufficient to provide a diuretic effect, lower blood volume, and prevent edema.
In another embodiment, the patient has asthma and the 20-HETE agonist is delivered as an inhalational therapy to dilate constricted airways.
In another embodiment, the patient may have pulmonary hypertension and 20-HETE or a 20-HETE agonist is infused to dilate the pulmonary circulation.
In another embodiment, the patient may have cerebral vascular injury, vasospasm, migraine or cluster headaches, stroke or cocaine-induced vasospasm and is treated with a 20-HETE antagonist to increase blood flow and relieve symptoms.
The present invention is also a pharmaceutical preparation comprising a compound selected from the group of 20-HETE agonists and antagonists and a pharmaceutically acceptable carrier. The preparation is preferably selected from the group of the 19-hydroxynonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid, 20-hydroxyeicosa 6(Z),15(Z)-dienoic acid, 20 hydroxyeicosa-5(Z),14(Z)-dienoic acid, dimethyl 20-HETE 21-hydroxyheneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid, N-methylsulfonyl-20-hydroxyeicosa-5(Z),14(Z)-dienamide, or N-methylsulfonyl-20-hydroxyeicosa-6(Z),15(Z)-dienamide and a pharmaceutically acceptable carrier.
It is a feature of the present invention that 20-HETE agonists and antagonists are provided. A general formula is also provided describing 20-HETE agonists and antagonists.
It is another feature of the present invention that therapeutic uses of 20-HETE agonists and antagonists are described.
Other features, objects and advantages of the present invention will become apparent after examination of the specification, claims and drawings.